Well, I have an IK WW barb. You really shouldn't dismiss it based on chance to hit if you aren't shoring up the AR in any way. It's not hard to do. I use Angelic Wings and Angelic Halo, but I'll quote from the guide I used...

Cold493 said:

The AR Dilemma of IK Barbs:

There seem to be alot of questions about this on the forums so i thought I would go ahead and put down some solutions for you guys. One option is the use of the Angelic Ammy/Ring combo which boosts your AR alot. The ring gives a +12 per level AR boost with two items. This is a common option for PvP barbs since AR is crucial there. I think there are ways to get around the AR problem without using the Angelic ring/ammy. My solution was the Ravenfrost for AR and dex along with other nice mods such as cannot be frozen and a Metalgrid amulet. I also ran into a few nice AR charms along the way which I kept. This should be enough AR for PvM. I believe I ended up with around 10k AR and an above 80% chance to hit which was good enough for me. I had only two GCs with AR one was +65 another +125. Hope that helps.

On the topic - you can just throw some points into dexterity untill you find good AR boosters like Ravenfrost, AR charms and Demonlimb - the enchant charges last for ~10 minutes so it's really manageable.
Later you can respec your stats anyway.
Also, stick two diamonds into your helmet - you'll replace them with something more useful as soon as you find a better solution to your AR problem.

Note that Immortal King's Will is unequippable by sorceresses. Only a barbarian can complete the full set. But some of the partial sets are still useful for a sorceress. I had an enchantress that borrowed gear from my IK barbarian for much of Nightmare difficulty, although she eventually gave all of the pieces back once she was higher in level.